When an apple is pressed, it produces fresh, unfiltered apple juice, also known as cider. If you want to extract the juice from numerous apples, it is best to use an apple press, particularly if you are making apple beverages. Build your own apple press with simple materials from the hardware store so you don't have to invest in an expensive commercial machine.
Set four of the 4-by-6 pieces up on the narrow sides in a box shape and bolt them securely at the corners with carriage bolts.
Lay the wood box you just created on its widest part. Put a 4-by-6 piece of wood up against one side of the square and line up the edges of this piece so they are in line with the box edges. Repeat this with the last 4-by-6 piece on the opposite side.
Place one of the hardwood cutting boards over the middle of the 4-by-6 frame, right in the center. Position the two loose 4-by-6 pieces on the edges so they support the edges of the cutting board. Drive two screws through each end of the cutting board to secure the cutting board into the 4-by-6 frame.
Make a small nick in the corner of the metal tray so it slides off the tray's edge. Use tin snips and continue making nicks until you reach the bottom edge of the tray. It should resemble a comb-like texture and appearance. Line the metal tray up with the cutting board so that when an apple on the metal tray is pressed, the juice will run right through the nicks. Drive screws through the metal tray at all four corners, securing it to the cutting board edges.
Fill the cheesecloth bag with sliced apples. Place the bag on the metal tray. Set the second cutting board on top of the bag, lining up the edges with the cutting board underneath.
Unscrew the bottle jack by turning the piston ram counterclockwise. Put the handle (a separate piece that comes with the bottle jack) into the pump shaft and carefully pump it up and down to raise the bottle jack until it is high enough to fit snugly on top of the cutting board sitting on top of the apples, directly in the center.
Use the tip of the bottle jack handle as a key for the valve (it looks like a flattened screw top located on the bottom of the bottle jack). The valve holds the pressure of the hydraulic piston when locked, and provides a release when opened. Turn the valve clockwise until it's tight to lock the bottle jack.
Place the bucket right below the metal tray nicks to catch the apple juice. Remove the handle from the pump shaft, and put the tip back into the valve to prepare to lower it. Crank the bottle jack counterclockwise so that the bottle jack presses down, squeezing all the juice from the apples into the bucket.